Rotation-release for rock drills



Apr. 117, 1923.

C. C. HANSEN ROTATION RELEASE FOR ROCK DRILLS Filec. July 25, 1920 ATTRNEY Patented Apr.a N, 3923.

ATENT CHARIJES C. HANSEN, OF EASTON, PENNSYLVANIApASSIGNQB, TINGEEEOLL-RAND COMPANY, 9F lJ'ElV 'YQRK, N. Y., A CORPORATION OF NEWJERSEY.

' BQTATIDN RELEASE FOR ROCK DRILLS.

i Application filed July as,

To all whom it may concern.

Be itknoWn' that 1, CHARLES C. HANSEN, a citizen of the United States,residing at Easton, in the county of Northampton and State ofPennsylvania, have invented certain new and useful Improvements inRotation Releases for Rock Drills, of which the following is aspecification.

This invention relates to rock drills of the 10 hammer type havingautomatic rotation for the drill steel, as for instance rifle barrotation, but relates more particularly to a device for releasing therotation when desired. The primary object of the invention is to enablethe operatorto change from a positive rotation to a slip rotation atwill, as for instance ihhard ground.

If the drill steel sticks it may be desirable to release the positiverotation and permit the hammer to operate with the slip rotation oroperate without rotating the .drill steel, until the normal positiverotation can be resumed, and my rotation releasing device accomplishesthese objects in a simple and efiicient 5 manner without complicationof. the parts. To these ends the invention is shown in one of itspreferred forms in the accompanying drawings, in which- Figure 1 isalongitudinal sectional elevation of a rock drill containing the device,

Figure 2 is a longitudinal detail sectional elevation taken through therear end of the1 piston hammer partly in perspective, an i Figure 3 is atransverse sectional view on the line 3-3 of Figure 1 looking in thedirection of the arrows. i

In order'to illustrate the invention a fluid pressure actuated rockdrill of the hammer 40 type having a riflebar rotation is illustrated,only so much of the operative parts being shown as will serve to makethe invention clear, the ports and passages for the distribution ofmotive fluid to the hammer cyll inder being omitted as forming no partof the present invention. 1

Referring to'the drawings, the drill cylinder A is mounted on the shellB in the a usual manner. The machine is fed to its work by meansof thefeed screw 0 having the feed screw nut D, the feed nut locknut E and thefeed crank F.

Fluid pressure is admitted to the drill cylinder .A and its operativeparts from the 1920. Serial No. 398,3?2.

inlet G and exhausted at the outlet H for operating the piston hammer Jreciprocating Within the cylinder. lhe drill steel K is carried in thechuck o1" rotation sleeve L within the front head 0 and the forwardextension of the shank ll of the piston hammer is provided with thestraight flutes Q engaging corresponding grooves in the rotation sleeveL. In this instance a front cylinder washer or piston hearing it islocated at the front end of the cylinder and forms a guide for thepiston shank.

The rearward reduced extension of the shank S of the piston is hollowand internally fluted with spiral flutesl engaging the rifle bar Uhaving a head V held between the rotation washer W and the back head Xof the machine. The rifle bar head V is provided with the rotation pawlsY adapted to engage the teeth of the rotation ratchet ring Z, which isadapted to be held fromrotation by means of the rotation. re-' leasingdevice a preferably in the form of a pin slidable into and out of enagement with the ratchet rotation ring Z.

The ratchet ring Z is preferably provided with a recess 72 in itsperiphery, adapted to register with the recesses 0 and d in the cylinderA and back head X respectively of the machine. The pin a is convenientlyarranged to slide longitudinally into the back head X and is providedwith a cylindrical enlargement or head e for engaging the ratchet rin Z.Engagement between the back head ratchet Z and cylinder A by the pin a,having the enlargement e is thus effected at the point of juncture ofall these parts, locking the back head X and ratchet Z together byasingle means at a common point. A spring f is adapted to becompressedbetween the head e of the pin and a shoulder g in the aperture it withinwhich the head e slides. The pin a is also provided with a handle groove0 when the pin is in locking position as indicated in Figure 2. When thepin is withdrawn to release the rotation as indicated in. Figure 1, thestop pin It is rotated and may lie against the back head to hold the pinin withdrawn position.

In the operation of the device the drill steel is rotated through therifle bar rotation in this instance on the back stroke or up or button jand a stop is provided on the shank of the pin enters the engage strokeof the piston and this is a positive rotation when the pin a is inlocking pos1-' tion as indicated in Figu rifle bar U is then heldstationary as the rotation ratchet ring Z cannot turn. In case it isdesired to change from positive to slip rotation, the pin a is withdrawninto the position indicated in Figure 1 thus releasing; the rotation andpermitting the rotation ratchet ring Z to slip or rotate relatively tothe drill casing. There may be a partial slip in which case there willbe apartial rotation of the drill steel, but in case the resistance torotation in hard ground is sufficient to overcome the frictionalengagement between the rotation ratchet ring and the parts between whichit is held, the hammer will operate without rotating the drill steel.The rotation releasing pin a is again moved into engagement with therotation ratchet ring when normal positive rotation is to be resumed.

I claim:

1. A rock drill of the hammer type having rifle bar rotation for thedrill steel including a drill casing, a back head a rotationratchet rihaving a' recess in its periphery adapt to register with a' lookingrecess in the drill casing, a spring pressed pin carried in the backhead in 1ongitudinal alignment with the drill casing, said pin adaptedto enter said recesses and said ratchet ring, casing and back head at apoint of juncture of said ratchet ring, casing, andback head forproducing positive rotation of the drill steel, but removable therefromto release the rotation and permit slip of the ratchet ring relative tothe drill casing.

2. A rock drill of the hammer type havre 2 because theat a point ofjuncture of specification.

ing rifle bar rotation for the drill steel including a drill casing, aback head a rdtation ratchet ring having a recess in its peripheryadapted to register with a looking recess in the drill casing, as ringpressed pin mounted in the back bee and a cylindrical enlargement at theend of said pin adapted to enter said recesses and engage said ratchetring, casing and back head said ratchetring, casing and back head forproducingpositive rotation of the drill steel, but removable therefromto release the rotation .and permit slip of the ratchet ring relative tothe drill casin and means for maintaining said pinin wi drawn position.

3. A rock drill of the hammer type havin rifle bar rotation for thedrill steel,'a cy inder casing, a back head for the casing,

said rifle bar rotation including a rotation ratchet ring havin a recessin its periphery cess in the interior of the cylindercasing a recessinsaid back head, and'a' spring pressed pin carried in said recess vbeingin longitudinal alignment with the drill casing and having a cylindricalhead at its inner end adapted to entersaid re istering recesses in theratchet ring and cy inder casing at the point of juncture of said partsfor producing positive rotation of the drill steel, means forwithdrawing the pin into the back head to release the rotation andpermit slip of the. ratchet ring relative to the drill casing, and meansfor locking said pin in retracted position.

In testimony whereof I, have signed this CHARLES c. HANSEN.

adapted to register with a locking re-

